1. Field of the Invention
This invention relates to a cylinder block of an automotive internal combustion engine, configurated to reduce vibration noise emitted therefrom.
2. Description of the Prior Art
In connection with automotive engine cylinder blocks, they are usually formed with a so-called skirt section which is integral with the side wall sections of the cylinder block and defines thereinside the upper part of a crankcase chamber. The skirt section is formed at its lower part with a flange to which an oil pan is secured. However, such a conventional cylinder block is usually not provided with any special measure to increase the rigidity against flexure and torsion applied to the cylinder block. Accordingly, the cylinder block tends to generate flexural and torsional vibrations, thereby emitting vibration noise from the cylinder block itself. Additionally, such cylinder block vibration induces vibration of the oil pan and the like covers, thus further increasing noise emission from the engine.